//close btn
.btn{
    background-color: rgba(0, 0, 0, 0.5);
    line-height: 2;
    color: #fff;
    padding: @scale-base 3*@scale-base;
    border-radius: 20*@scale-base;
    transition: 0.5s @standard-curve transform;
    user-select: none; 
    &:hover{
        cursor: pointer;
    }
    &.close{
        position: fixed;
        bottom:2*@scale-base;
        left:50%;
        transform: translate(-50%,0);
    }
    &.hide-out{
        transform: translate(-50%,80px);
    }
}
